The present invention relates to the separation of an immiscible or insoluble fluid mixture into its less dense component and denser component. Preferably, the immiscible or insoluble fluid mixture comprises a grease-oil/water mixture, the less dense component comprises a grease-oil component, and the denser component comprises a gray water component. The present invention also relates generally to a drain assembly for an appliance and, more particularly, to a drain assembly for a commercial kitchen appliance.
A combination oven uses both steam and radiant heat in the cooking process. Typically, these ovens use a steam kettle to generate steam for the cooking chamber. The steam kettle must be periodically flushed to remove any limes, scales, or precipitate from the steam kettle. The flush cycle completely purges the water in the kettle by means of an internal pump or line pressure arrangement. This flush sequence can propel twenty to twenty-five liters of water through the kettle and into the combination oven. The flush water exits through a discharge port in the oven in a short (30 to 60 second) time frame. These ovens typically use as a condensate discharge port a pipe with an outer diameter of about 50 millimeters. Therefore, the entire pipe cross section must be available to allow for such a high volume of water to be discharged in that time.
During the cooking process, condensed steam and grease exit the cooking chamber of the oven through the same discharge port in the oven as the flush water flow. This flow of condensed steam and grease exits at a much lower flow rate. Also, typically this flow of condensed steam and grease has been directed through the same drain line as the flush water, both, which are eventually discharged into a sewage outlet. In most applications, the grease tends to solidify within the discharge port. Once that blockage occurs, the large flow of flush water cannot escape the discharge port at a proper rate of speed. A resultant backup of flush water may cause water to pool in the bottom of the appliance or leak out of the appliance through areas other than the discharge port. This backup may also cause contamination of cooking racks and/or the food products placed on the cooking racks. Thus, there is a need to ensure that the discharge port remains clear from any grease or other residue.
Similar grease discharges from rotisserie ovens can cause similar discharge port and/or drain line clogs. Rotisserie ovens have pans of water in them to humidify and to collect grease drippings. The water overflows to a discharge port, typically a tube that can clog with grease. Thus, there is also a need to ensure that the discharge port of a rotisserie oven remains undestructed.
Numerous devices have been described for the separation of liquids having different densities. Although such devices appear to be effective, there is a need for an improved device particularly well suited for the remote servicing of appliances, particularly, kitchen appliances.
U.S. Pat. No. 5,518,610 discloses an oil-water separation device that uses a vacuum to draw an oil-water mixture through an oil coalescer. The oil and water depart the device through separate paths.
U.S. Pat. No. 5,405,538 discloses an apparatus for removing grease from a grease trap separator 10 containing grease and water and transferring the grease to a transfer tank 24. A discharge pipe 36 extends from the transfer tank 24 to a remote location such as a holding tank or truck tank. A pump 34 communicates with the separator 10 and the transfer tank 24 through a tube 26 to facilitate the movement of grease from the separator to the transfer tank 24 through a tube 16 and eventually to the remote location through discharge pipe 36 without grease, oil, or gross solids passing through pump 34. Check valves 22 and 44 and sensor 32 and 42 in concert with pump 34 facilitate the operation of the apparatus. Again, oil and water depart through separate paths.
U.S. Pat. No. 4,960,513 discloses a separator including a tank that allows a mixture of oil and water to separate and then discharges the two fractions. The separator is automatically filled when a first float indicates a low level. A second float close to the bottom of the tank has a density such that it will just float in water. The presence of oil causes the second float to sink. A switch connected to the second float operates either a water valve when in a risen position, or an oil pump when in a fallen position. Again, the oil and water depart through separate paths.
U.S. Pat. No. 4,426,293 discloses a method and apparatus for removing oil from water by gravity. A sensor 22 that determines the bottom of the oil layer in tank 12 (oil/water interface) opens and closes valves to facilitate the discharge of separated oil and separated water and the filling of mixed oil and water (see e.g., col. 4, lines 41-50). The oil exits line 60 and the water exits line 54.
U.S. Pat. No. 3,713,778 discloses a separating funnel device for separating at least two immiscible liquids of differing specific gravities. FIG. 3 depicts a device having separate conduit and valve. The lighter fraction is drained while the heavier fraction stays in the funnel, unless separately removed.
U.S. Pat. No. 306,171 discloses a compound faucet that facilitates the withdrawal of liquids of different specific gravity from a vessel or vessels independently of each other and at will. Each liquid may be delivered into different receiving vessels, as desired. The faucet is described in connection with the separation of milk and cream.
Thus, there is a continuing need for a separator for the remote servicing of appliances that segregates an immiscible or insoluble fluid mixture into a less dense component and a denser component that overcomes the above problems of the prior art. More specifically, there is a need for a separator for the remote servicing of commercial food preparation appliances that segregates grease-oil/water mixtures into a grease-oil component and a gray water component. It is also apparent that there is a need for a system that separates the grease-oil component, which is later appropriately disposed, from the gray water component, which is disposed into a drain or a sewer.